With advance of non-volatile memory (e.g., flash memory), attempts have been made to use non-volatile memory as data storage, for example, flash memory drive, solid state drive (SSD), etc. One of the most commonly used interfaces for the non-volatile memory devices is based on a specification referred to as Universal Serial Bus (USB). Not only personal computers have adopted USB as standard method for connecting peripherals, but other devices (e.g., smartphone, video game console, personal digital assistant (PDA) and power cord for charging).
FIG. 1A is a schematic circuit block diagram illustrating an electronic data storage medium disclosed in the parent application. The electronic data storage medium with fingerprint verification capability can be accessed by external computer 109 using input/output interface circuit 105, which may use a USB or similar interface. The electronic data storage medium can be located inside or outside of the external computer 109. Card reader 106 may be attached to external computer 109 or may act as a substitute for external computer 109 through the host computer link 108 with a USB-Attached-SCSI (UAS) bus, which has one set of two pairs of differential serial buses:                (i) first pair differential serial bus with a first pin carry “+” signal and a second pin carry “−” signal, and;        (ii) second pair differential serial bus with a first pin carry “+” signal and a second pin carry “−” signal.        
UAS protocol is used in conjunction with the latest USB 3.0, which specifies a maximum data transfer rate of five Gigabits/second (Gb/s) via the two pairs of differential serial bus.
Card reader 106 accepts card body 101. The card reader interface can connect with various standard buses including, but not limited to, Secure Digital (SD) bus, Compact Flash (CF) card, Serial ATA (SATA) bus, and Serial SCSI (SAS) bus. Electronic data storage medium packaged in card body 101 includes processing unit 102, memory device 103, security unit 104, and input/output interface circuit 105. Additionally, card reader 106 can connect to the host computer 109 with a link 110 substantially similar to the computer link 108.
Memory device 103 can be a solid state flash memory device rather than a rotational hard disk drive. Using flash memory provides lighter weight, lower power, and more rigidity than the rotational hard drive. Memory device 103 is generally configured for storing data files such as text, video and/or audio files. Data files may need security and encryption/decryption that can be processed by security and encryption/decryption unit 104. Security unit 104 may be configured for AES, IEEE 1667, fingerprint sensor, or other types of security functions, such as encryption and decryption and password verification or management. Processing unit 102 connects to other components and can operate in various modes, such as a programming mode, a data retrieving mode, and a data resetting mode. Power converter 107 can be a DC-DC (direct-current to direct-current) converter that converts from a higher voltage, such as 5 volts, to a lower voltage such as 3.3 or 1.8 volts or some other value that can be used by other units.
Flash memories use non-volatile memory cells such as electrically-erasable programmable read-only memory, (EEPROM), but are not randomly accessible at the byte level. Instead, whole pages or sectors of 512 bytes or more are read or written together as a single page. NAND flash memory is commonly used for data storage of blocks. Pages in the same block may have to be erased together, and limitations on writing may exist, such as only being allowed to write each page once between erases.
These small portable electronic devices often are able to connect to a host computer such as a personal computer (PC). While a proprietary connector may be used, a connector for a standard expansion bus is preferable. USB is often used to connect such portable flash-memory devices to a PC.
The USB 3.0 bus standard uses two pairs of differential lines that are full-duplexed, or used for transmission in both directions. The older USB 2.0 standard provides that the host, such as the personal computer, controls the bus as the bus master, while USB devices plugged into the host act as slave devices. A USB controller on the host PC generates data transfer transactions and waits for USB devices to respond, either by transmitting requested data to the host, or by writing host data into the USB device's memory.
Often a host system contains several different buses. For example, the host may have a Peripheral Components Interconnect Express (PCIE) bus, a Universal-Serial Bus (USB), an Integrated Device Electronics (IDE) bus, and an AT bus. Peripherals using the Small-Computer System Interface (SCSI) that connect to a host through USB are known as USB-Attached-SCSI (UAS).
Devices to convert one bus type to another bus type are known as bridges. Legacy host systems are not equipped for the newer bus protocols since these legacy systems are older and were designed before the new bus protocols were available. Bridges are often slow since all protocol layers may be present and are traversed. Data packets must flow up through the stack of protocol layers and then back down another stack of protocol layers for the other bus. When multiple bus standards are present on a host system, several bridges may be used in series, causing increased delays for multiple successive format conversions by multiple bridge devices.
FIG. 1B is a block diagram of host with an Enhanced USB (EUSB) receptacle that supports single-mode EUSB communication. EUSB card 111 can be plugged into EUSB receptacle 122 of host 121. Host 121 is an electronic device, for example, a cell phone or a digital camera, etc. EUSB receptacle 122 supports single-mode EUSB communication. Terms, USB, Enhanced USB and USB 3.0 are interchangeably used herein in this document. Unless explicitly stated as USB 2.0, all other references are referred to USB 3.0. Host 121 has a processor system 125 for executing programs such as EUSB management. EUSB protocol processor 124 performs protocol processing such as conversions to EUSB or USB 3.0 over bus 123 for host processor system 125. EUSB card 111 is a EUSB device with a plug that supports EUSB communication. EUSB card 111 has EUSB protocol processor 114 for executing programs including device initializations and bus-response programs. Single-personality bus interface 113 communicates processed data from EUSB protocol processor 114 using the EUSB protocol to its plug 112. Data is ultimately stored in flash memory array 115.
FIG. 1C is a block diagram of a USB UAS card reader with a flash-serial buffer bus 140 in parallel with the CPU bus 138. One or more flash-card controllers 150, 154 connect to both CPU bus 138 and to flash-serial buffer bus 140. When a flash-memory card is inserted, embedded, or surface mounted into ‘slot-A’ of card reader 190, flash-card controller 154 can transfer data, while when a flash-memory card is inserted into ‘slot-B’, flash-card controller 154 can transfer data. CPU 180 sends commands over CPU bus 138 to flash-card controllers 150, 154 using their slave ports 151, 155 and CPU master port 185.
Therefore, it would be desirable to have a flash memory device that uses the faster extended modes of operation to take the advantage of additional pipes provided in UAS and USB 3.0.